External Quality Assurance of Platelet Function Assays: Results of the College of American Pathologists Proficiency Testing Program.

Context.—: The College of American Pathologists (CAP) developed proficiency testing for platelet function assays by using blood collected by the participant added to challenge tubes containing either saline (normal) or tirofiban (abnormal).

Objective.

Primary Central Nervous System Histiocytic Sarcoma Arising After Precursor B-Cell Acute Lymphoblastic Leukemia.

Histiocytic sarcomas (HSs) are rare malignant neoplasms derived from histiocytes that may be associated with other hematolymphoid neoplasms. Histiocytic sarcomas rarely occur in the CNS and have not previously been reported in conjunction with prior B-cell lymphoblastic leukemia. We report the case of a 23-year-old man who presented with primary CNS HS 7 years after achieving remission for precursor B-cell acute lymphoblastic leukemia (B-ALL).

Tissue-preserving antibody cocktails to differentiate primary squamous cell carcinoma, adenocarcinoma, and small cell carcinoma of lung.

Context: With the availability of cell type-specific therapies, differentiating primary lung squamous cell carcinomas (SCCs) and adenocarcinomas (ACAs) has become important. The limitations of small sample size and the need to conserve tissue for additional molecular studies necessitate the use of sensitive and specific marker panels on a single slide.

Objective: To distinguish SCC from ACA and small cell carcinoma (SmCC) of lung using 2 novel tissue-conserving cocktails.